The present invention relates generally to the field of dynamic magnetic information storage and retrieval, and more particularly to a monolithic multichannel tape head and actuator for high density magnetic recording.
A typical approach for enabling higher data rates in magnetic tape technology is by adding active channels to the tape heads. However, this approach is becoming increasingly difficult to implement as heads, flex circuits, and electronics become more and more congested due to a need for packaging more I/O into the limited space of the head and head assembly. Typical solutions have included implementing head modules having a reduced footprint, along with associated cabling, connections, connectors, and ASICs. Disadvantages of this approach may include increased complexity and component cost, and lower yields and reliability. The problem is compounded in conventional multi-module tape heads. Typically, conventional tape heads are comprised of two or more modules configured to perform bi-directional read verify after writing.
The need for redundant magnetic transducers for enabling read-verification during writing may result in difficulties meeting packaging, electronic, and thermal requirements. For example, a tape drive with 16 active channels, such as a typical tape drive operating in accordance with Linear Tape-Open sixth generation (LTO-6), may contain 16 writer and 16 reader transducers in each of two head modules for bidirectional read-while-write operation, thus containing 64 channels and illustrating 2× redundancy. Achieving higher data rates, for example, by increasing the number of active channels to 64 while maintaining 2× redundancy, results in increasing the number of writer and reader transducers to 64 on each of two heads, resulting in 256 channels. Such a head assembly requires 256 pairs of 110 bonding pads. Given the space constraints in the current form factor products, this may present challenges in routing of wire bond leads, increased on-chip lead length and resistances, heat generation, and production yield. In some tape heads, read verify is performed by a separate, independently track-following head, but even so, the heads typically contain two or more modules to enable bi-directional operation. Known solutions to these problems have been incremental, and have included reducing module size, but this is increasingly difficult to do, as modules become more fragile and difficult to manufacture.
Space available for cabling is also limited. Bulky cables may impact actuator performance due to mechanical bias, stress, and coupling effects. In addition, cable trace geometry may be pushed to current design and manufacturing limits. Another issue is limitations of the actuator to accurately perform track-following operations as channel density increases due not only to stiff, bulky cables, but also to the size of the head moving mass. Multi-module heads only compound this problem. Yet another issue with conventional multi-module tape head-actuator assemblies is that their size does not enable close spacing of the assemblies, as these may be bulky due to the need to contain two or more modules and all the associated cabling.